With its decision to nullify the results of last month's presidential election, Kenya's top court has invalidated the votes of some 15 million citizens. It has also struck a blow for democracy that will reverberate across Africa.

Now comes the hard part: Holding new elections within 60 days that are untainted by the irregularities, intimidation and violence that have scarred past contests.

The court's unprecedented decision -- the first time the re-election of an incumbent president has been reversed anywhere on the continent -- came in response to challenger Raila Odinga's complaint that President Uhuru Kenyatta's re-election victory was abetted by vote-rigging. The court found "irregularities and illegalities in the transmission of results" -- charges backed by independent observers (although there were also reports that the voting process was credible).

The court has yet to release its full written judgement. Yet what matters is that the process is working: One candidate filed a complaint, the court issued a decision, and the other candidate agreed to abide by it. The judiciary has affirmed its independence and moved to defend the integrity of Kenya's electoral process, bolstering the confidence of both voters and investors.

These developments also mark a deeper entrenchment of democracy in Africa, as demonstrated by the strength of opposition parties in Gambia, Ghana, Nigeria, Senegal and South Africa. It should encourage supporters of democracy and transparency in Zambia, where an opposition candidate was jailed on treason charges for contesting election results, and in the Democratic Republic of Congo, where President Joseph Kabila is trying to prolong his stay in power.

The danger is that the run-up to new elections in Kenya's highly polarized environment, and the inevitable disappointment of the losing side, will trigger violence. To give clear guidance to Kenya's electoral commission, the court needs to release its full ruling as soon as possible. A credible election demands a commission that commands greater public confidence. A working and secure electronic vote tallying system should not be beyond the reach of a country known for its digital innovations.

The new election will be closely fought. But the court's intervention should strengthen the public's faith in Kenya's judiciary and, by extension, its political process. That's a victory for all sides.